七ツ金 Nanatsugane / Seven Metals
What is Nanatsugane in Japanese Katana terminology?
This is a type of metal fitting used to secure the leather of the Obitori (belt holder) when wearing a Tachi (a type of Japanese sword). Three are attached to the Ichinoashi (first foot) on the handle side, and four are attached to the Ninoashi (second foot) on the Saya-jiri (scabbard tip) side, hence the name ""Nanatsugane"" (seven metals). They often feature carvings or family crests, serving a significant decorative role.